The present invention relates to an analog-to-digital converter and more particularly to a converter for converting a high frequency video signal to a digital signal by peak detecting the video input voltage during sample times.
The prior art in respect to analog-to-digital conversion in general, is voluminous. Most of the known conversion devices include triggered circuitry such as flip-flops, counters, and the like, however heretofore available converts can process only analog signal less than 1 MH.sub.z. Also, there are no heretofore known converters which have peak detecting capability.
One device for converting an analog signal to a binary signal is shown and described in U.S. Pat. No. 3,859,631, entitled, "Method And Apparatus For Decoding Binary Digital Signals", which issued Jan. 7, 1975, to Robert S. Holmes and Walter M. Katz. In this patented device, a phase lock loop is provided for locking the operation of a counter onto a multiple of the bit frequency. The counter is preset at the start of each bit and logic circuitry is provided for causing the counter to operate in a predetermined manner depending upon the level of the signal in the bit cell and whether that signal is in the first or the second half of the bit cell. The value of the cell is either a one or zero depending upon the contents of the counter at the end of the bit cell as determined by the phase lock loop.